From what I am understanding here, the topic creator's request is to have Toady implement the structures that modders require to do their work better. This isn't about forcing Dwarf Fortress to use a standardized tileset or anything like that, the goal is to make it so that bugs are minimized while allowing modders to change more things. While it is true that it would take Toady some effort to do this, it would also open new doors for the graphical modders, who require a foundation to do their work. The sooner the structure is in place, the more quickly these people can expand their tilesets with fewer flaws.
Furthermore, graphics are a part of gameplay. To the ASCII grognards, the ASCII is a means of visualizing things in a customized way for themselves. Unfortunately, most people desire to quickly assess and understand the events that occur in the game, and ASCII is reaching it's limits for showing this level of detail. In the User Interface thread, someone mentioned that there were at least 9 different meanings for "C" in the game, which complicates the game. By requiring players to learn ASCII while making symbols to take on multiple meanings is going to tax the abilities and patience of players. This would hurt the game, which would harm the community. Graphics packs like Mike Mayday's is going to be very helpful in off-setting these issues for future players.